Tool and process for chrome plating a vehicle wheel surface

ABSTRACT

A cutting tool having a crystalline tip is pressed with a uniform pressure against the outboard surface of a vehicle wheel as the wheel is rotated. The smoothed wheel surface is then chrome plated to provide a cosmetic finish to the wheel face.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of co-pending application U.S. patentapplication Ser. No. 10/756,856 filed Jan. 14, 2004, which was aContinuation-in Part of U.S. patent application Ser. No. 10/309,726filed Dec. 4, 2002, now U.S. Pat. No. 6,733,366, which was a divisionalof U.S. patent application Ser. No. 09/725,528 filed on Nov. 29, 2000,now U.S. Pat. No. 6,540,450, and claimed the benefit of U.S. ProvisionalPatent Application No. 60/246,663 filed on Nov. 8, 2000, and claims thebenefit of U.S. Provisional Patent Application No. 60/440,914 filed onJan. 17, 2003,and of U.S. Provisional Patent Application No. 60/450,013filed on Feb. 26, 2003, for the new matter contained therein.

BACKGROUND OF INVENTION

This invention relates in general to vehicle wheels and in particular toa method and cutting tool for machining a portion of the vehicle wheeloutboard face to produce a smooth surface and then chrome plating thesmooth surface.

Vehicle wheels typically include an annular wheel rim and a circularwheel disc. The wheel disc can be formed across the outboard end of thewheel rim or recessed within the wheel rim. The wheel rim is adapted tocarry a pneumatically inflated tire. The wheel rim has inboard andoutboard tire retaining flanges formed on the ends thereof which extendin an outward radial direction to retain the tire on the wheel. Inboardand outboard tire bead seats are formed on the outer surface of thewheel rim adjacent to the corresponding tire retaining flange to supportthe tire wall beads and form an air-tight seal therewith. The wheel rimalso includes a reduced diameter deep well between the tire bead seatsto facilitate mounting the tire upon the wheel.

The wheel disc includes a central wheel hub for mounting the wheel upona vehicle. The inboard face of the wheel disc hub is typically machinedto form a flat surface to assure good contact between the wheel disc andthe vehicle wheel hub. A pilot hole and a plurality of wheel stud holesextend through the wheel hub. The pilot hole is centered on the hub andthe stud holes are spaced equally about a bolt hole circle which isconcentric with the pilot hole. The pilot hole can receive the end of anaxle while the wheel stud holes receive wheel studs for attaching thewheel to the vehicle. The wheel disc also typically includes a pluralityof wheel spokes which extend radially from the wheel hub to the wheelrim and support the hub within the rim.

Referring now to the drawings, a flow chart for a wheel manufacturingprocess is shown in FIG. 1. In functional block 10, a wheel is cast in asingle piece from a light weight metal such as aluminum, magnesium ortitanium, or an alloy of a light weight metal. Such wheels are becomingincreasingly popular because they weigh less than conventional steelwheels and can include outboard wheel disc faces which are formed in apleasing aesthetic shape. One piece wheel castings are usually formed bya gravity or low pressure casting process. The wheel castings arefinished by machining to a final shape.

Two separate machining stations are typically used to finish a wheelcasting. In functional block 11, the outboard end of a rough wheelcasting is clamped to the face of a first wheel lathe for a first set ofmachining operations. A wheel lathe is a dedicated machine designed tofinish wheels. Wheel lathes typically include a plurality of cuttingtools mounted upon a lathe turret. The turret is indexed to sequentiallymove each of the tools to the surface of the wheel casting. Wheel lathesare usually operated under Computer Numerical Control (CNC) tosequentially perform a number of related machining operations. Forexample, a wheel lathe turret can be equipped with a turning tool, afacing tool and a drill bit and the wheel lathe can be programmed tosequentially turn, face and bore a wheel casting. The wheel lathe facetypically includes a chuck having a plurality of jaws which grip theoutboard wheel retaining flange and tire bead seat. Consequently, theoutboard wheel rim end is not finished during the first set of machiningoperations.

The outside and inside surfaces of the wheel rim are turned to theirfinal shapes and the inboard surface of the wheel hub is faced infunctional block 12. Additionally, the inboard end of the wheel rim isfinished. The partially finished wheel casting is removed from the firstwheel lathe, reversed and clamped on a second wheel lathe for a secondset of machining operations in functional block 13. During the secondset of machining operations, the inboard wheel flange and tire bead seatare gripped in the jaws of the wheel lathe chuck, exposing the outboardsurface of the wheel disc and the outboard end of the wheel rim formachining.

In functional block 14, the second wheel lathe turns and faces theoutboard wheel face. During these operations, the outboard tireretaining flange and the outboard tire bead seat also are turned tofinal shapes. The surface of the hubcap retention area is machined tofinal shape and the stud mounting holes are drilled through the hub infunctional block 15. Alternately, the wheel casting may be removed fromthe wheel lathe and the drilling operation completed at another workstation.

During the facing and other machining operations, very fine grooves areformed in the surfaces of the wheel. Accordingly, the surface of thewheel is typically subjected to a finishing step, as shown in functionalblock 16. A typical finishing process involves polishing the wheelsurface to smooth the grooves and provide a lustrous appearance to thesurface of the wheel. The polishing is usually followed by applicationof a clear coating to protect the polished wheel surface.

A typical polishing and chrome plating operation is illustrated by aflow chart in FIG. 2. Polishing typically involves a first step of roughbuffing with an abrasive compound as shown in functional block 20. Thebuffed wheel is degreased in functional block 21. One frequently usedmethod of degreasing involves passing the wheel through a chamber whichis filled with a solvent vapor. The solvent vapor condenses upon wheel,covering the entire wheel surface. Once the solvent has had a sufficienttime to dissolve any surface grease, the solvent is washed from thewheel to complete the degreasing. As shown in functional block 22, thewheel is then wet polished with a liquid lubricant for the polishingabrasive. The wheel is usually rotated and rotating polishing wheels areapplied to the surface while a slurry of polishing abrasive and acarrier fluid is applied to the wheel surface. Next the wheel is rinsedin functional block 23. Typically, deionized water is used for therinse.

The substances utilized during wheel polishing are generally toxic innature. Accordingly, it is common practice to ship the wheels to apolishing contractor who employs safety procedures to protect personnel.The contractor is also equipped to dispose of the toxic wastes generatedby the polishing operations.

The polished wheel surface is buffed in functional block 24. Typically,the buffing step utilizes a rag and buffing compound to create a surfacesmooth and shiny enough to achieve the generally accepted smoothness andclarity required for chrome plating an aluminum wheel. Finally, a layerof chrome plating is applied to the wheel in functional block 25. Thechrome plating may be provided at the polishing facility, or the wheelmay be shipped to a chrome platter.

SUMMARY OF INVENTION

This invention relates to a method and improved cutting tool formachining the finished a portion of an outboard wheel face to produce asmooth surface and then chrome plating the smooth surface.

As described above, it is known to polish and buff an aluminum wheelsurface prior to chrome plating. However, such processes requireabrasives and solvents. The polishing and buffing can create slightwaves or subtle uniform variations in the polished surface due toharmonic oscillations of the power equipment used and differing amountsof work pressure exerted on the surface due to different elevations ofthe geometric designs of the wheel surface. When polishing and buffingis done by hand, the variations are more random due to fatigue of thehuman muscles and the inability to make exact dimensional repeatedmotions. Thus, conventional polishing and buffing methods are known toproduce a slightly distorted reflection that is similar to lookingthrough an antique glass pane that has experienced some flow of itsmolecular structure. Such flow can cause a certain amount of refractionor deflection of the light rays passing through the glass. Therefore, itwould be desirable to provide a process for smoothing a wheel surfacethat does not require conventional polishing and buffing.

Furthermore, typical solvents include trichloroethylene,trichloroethane, sulfuric acid and perchloroethylene, which are toxic.Additionally, the lubricants for the abrasives can include animallubricants such as grease and lard. The polishing wheels can produceair-borne lint during the polishing and buffing operation. Accordingly,it is necessary to protect the workers from these materials and collectand dispose of the residues. Because of the complexity of the polishingoperations and the need to appropriately control the environmentalimpact of the materials utilized, wheels are often shipped to an outsidecontractor for polishing. This involves additional time and expense.Thus, it would be desirable to smooth the wheel face without polishingthe wheel.

The present invention contemplates a vehicle wheel comprising an annularwheel rim portion and a wheel disc formed across the wheel rim. Thewheel disc has an outboard face which includes a smoothed portion toprovide a pleasing cosmetic appearance. It is further contemplated thatthe smoothed portion of the wheel disc face can extend over the entiresurface of the wheel disc outboard face. An optional protective coatingcan be formed over the smoothed portion of the wheel disc face.

The present invention further includes a process for forming adecorative surface upon a vehicle wheel face which comprises providing amachined vehicle wheel including a wheel rim and having a wheel discextending radially across the wheel rim. The machined wheel is mountedin a lathe. The wheel is rotated while an improved cutting tool having ahardened tip is urged with a uniform cutting pressure against theoutboard surface of the wheel disc to smooth at least a portion of thewheel disc surface. In the preferred embodiment, the hardened tip isformed upon an insert of poly or mono crystalline material that ismounted on one end of the cutting tool. The invention also contemplatessmoothing the entire outboard face of the wheel disc. Subsequent tosmoothing the wheel face, the smoothed portion of wheel face is chromeplated.

Various objects and advantages of this invention will become apparent tothose skilled in the art from the following detailed description of thepreferred embodiment, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is is a flow chart for a known process for manufacturing a onepiece vehicle wheel.

FIG. 2 is a flow chart for a known process for polishing and chromeplating a one piece vehicle wheel.

FIG. 3 is a sectional view of a vehicle wheel and illustrates a processfor finishing the vehicle wheel face in accordance with the invention.

FIG. 4 is a plan view of a wheel surface finishing tool in accordancewith the invention that is used in the finishing process illustrated inFIG. 3.

FIG. 5 is a side elevation of the surface finishing tool shown in FIG.4.

FIG. 6 is an enlarged partial side elevation of the tool shown in FIG.5.

FIG. 7 is a flow chart for manufacturing a one piece vehicle wheel whichutilizes the surface finishing process illustrated in FIG. 3.

FIG. 8 is a flow chart for an alternate embodiment of the manufacturingprocess shown in FIG. 7.

FIG. 9 is a flow chart for another alternate embodiment of themanufacturing process shown in FIG. 7.

FIG. 10 is an alternate embodiment of the wheel surface finishing toolshown in FIG. 4.

FIG. 11 is a side elevation of the surface finishing tool shown in FIG.10.

DESCRIPTION

Referring again to the drawings, there is illustrated in FIG. 3, asectional view of a one piece wheel 30 having an outboard surface 31 anda process for finishing the wheel 30 in accordance with the presentinvention. The finishing involves cutting the wheel surface 31 with animproved cutting tool having a unique geometry that will be describedbelow. An increased brightness or shine of the wheel surface is expectedfrom the cutting process. Thus, the present invention is directed tosmoothing the visible portions of a wheel face to cosmetically improvethe appearance of the wheel face.

As shown in FIG. 3, the wheel 30 includes an annular wheel rim 32. Awheel disc 33 which includes the outboard surface 31 extends radiallyacross the outboard end of the wheel rim 32. The invention contemplatesmounting an inboard end of the wheel rim 32 in the jaws 34 of a lathe ora spinner chuck of a wheel lathe (not shown).

The wheel 30 is rotated about an axis 35, as shown by the arrow in FIG.3, by the wheel lathe. An improved cutting tool 40 is mounted upon atool holder 41 that is secured to a wheel lathe turret (not shown). Thewheel lathe urges the cutting tool 40 against the outboard wheel face 31with uniform or equalized cutting pressure to simultaneously removematerial from the wheel face 31 and smooth the cut surface. In thepreferred embodiment, programmable machine tools are utilized to assurethat the cutting pressure is equalized for all elevations of thegeometric shape of the wheel being finished. The tool 40 is traversed ina radial direction from the outboard end of the wheel rim 32 across thewheel face 31. The tool 40 moves alternately toward and away from thecenter of the wheel disc 33, as shown by the small arrows in FIG. 3. Asthe tool 40 moves across the wheel face 31, the tool 40 also is movedaxially to follow the contour of the wheel face 31. The inventionfurther contemplates that the improved cutting tool 40 can be inclinedto smooth all possible inclinations of the wheel face 31, such ashorizontal, vertical or inclined, as illustrated in phantom in FIG. 3.Additionally, the tool 40 can be advanced in an axial, or radial,direction to increase the amount of material removed from the wheel face31. Liquid coolant is applied to the working surface by a conventionalsupply means (not shown). As will be described below, a portion of thesurface of the wheel face 31 is melted and then resolidified as the tool40 passes thereover to form a smoothed portion of the wheel face 31.

As shown in FIGS. 4 and 5, the improved cutting tool 40 is a speciallymodified face cutting tool. The tool 40 has a rhombic shaped body 42having a bore 43 formed therethrough which receives a fastener (notshown) for securing the tool to the tool holder 41. The tool 40 isformed from a sintered carbide steel and includes an insert 44 insertattached to one end. The insert 44 is formed from a poly crystallinematerial which may be either naturally occurring or syntheticallyproduced. In the preferred embodiment, the insert 44 is formed from aPoly Crystalline Diamond (PCD) material. The insert 44 includes animproved cutting tip 45 on one end that contacts the wheel face 31 andworks the metal. The arrow in the upper left portion of FIG. 4 indicatesthe direction of movement of the worked metal relative to the cuttingtool 40. The insert 44 has a length L of about six mm.

The invention also contemplates applying a polycrystalline coating to asubstrate to form the tool insert (not shown). The inventors believethat either a diamond or ceramic coating may be utilized. The coatingwould be applied either before or after the geometry of the cutting tipis formed.

The present invention contemplates a special geometry for the cuttingtip 45. For comparison, a standard cutting tip is outlined by the dashedline labeled 46 in FIG. 4. While the standard cutting tip 46 issymmetrical about the centerline of the tool, the cutting tip 45 of theimproved tool 40 is non-symmetrical, having two different radii. Theleading edge of the tip 45 has a larger radius R₁ while the trailingedge of the tip 45 has a smaller radius R₂. Both radii R₁ and R₂ areperpendicular to the centerline of the tool 40. In the preferredembodiment, the leading edge radius R₁ is twice the trailing edge radiusR₂. Additionally, the leading edge radius R₁ is selected to be greaterthat the rate of feed per revolution programmed into the wheel lathe tocause multiple cutting of the wheel surface prior to the tangent pointof the tip 45. In the preferred embodiment, the leading edge radius R₁is 3.01 mm while the trailing edge radius R₂ is 1.5 mm. These radiicompare to a typical standard cutting tip radius of 1.0 mm. Thedirection of movement of the wheel being worked is indicated by thearrow in FIG. 4.

As best seen in FIGS. 5 and 6, the insert 44 is canted at an angle αrelative to the top surface of the tool body 42. In the preferredembodiment, the angle α is seven degrees. A flat land 48 is formedaround the upper edge of the insert 44. The land 48 is perpendicular, orhas zero rake, to the top surface of the tool body 42. Because theinsert 44 is canted relative to the tool body 42, the cutting edge ofthe insert 44 also forms an angle of α with the tool body top surface.Thus, the cutting edge of the insert 44 is maintained tangent to thesurface of the face of the vehicle wheel. The land 48 has a width W thatis in the range of between 0.076 and 0.254 mm with the preferredembodiment having a width in the range of 0.076 to 0.127 mm. The lowerportion 49 of the insert 44 and the tool body 42 are undercut at anangle β to allow removal of the cut material. The angle β is in therange of five to 15 degrees and is five degrees in the preferredembodiment.

The tool holder 41 is of conventional design but is formed of ananti-vibration material, such as, for example, machinable carbide tominimize vibration by avoiding resonance. Also, the tool holder 41 isdesigned for a minimum extension from the wheel lathe turret to increasethe rigidity of the smear cutting tool 40. Additionally, it iscontemplated that the associated wheel lathe includes a balanced chuck,centering, locating and clamping mechanisms.

During operation, the zero rake land of the insert tip 44 rubs the wheelsurface causing “work hardening” of the wheel metal. This differs from aprocess commonly referred to as “smear cutting” where a tool is draggedin a “backward” direction over the workpiece to only smooth the surface.The present invention contemplates advancing the tool 40 in a “forward”direction. The unique geometry of the improved cutting tool tip 45simultaneously removes material from the wheel face and smoothes thewheel face. In the preferred embodiment, the depth of material removedby the tool 40 is within the range of 0.05 mm to 0.1 mm. The frictionbetween the tool tip 45 and the wheel surface generates sufficient heatto cause microscopic melting of the surface metal. The friction betweenthe tool tip 45 and the wheel surface forces a small amount of themelted metal in front of the tip 45 and into any surface voids. Themelted surface metal then resolidifies. The melting and resolidificationof the metal can leave a bright surface that appears to have beenpolished.

The inventors believe that as a wheel solidifies following casting, alayer of oxidized metal is formed upon the surface of the wheel. Theoxidized layer is melted and quickly resolidifed during the cuttingprocess with the improved cutting tool 40. As a result, an oxidizedlayer does not have a chance to be formed. A similar process is utilizedto provide a lustrous surface finish to gold ingots. As a gold ingotsolidifies, the exterior surface becomes dull due to slight oxidation ofthe gold on the surface and impurities rising to the surface. A torch isused to heat and remelt the surface of the ingot to a semi-liquid state.The torch is quickly removed as soon as the ingot surface becomes shiny.This process for gold ingots is typically referred to as tinning. Theinventors have found that if the feedrate for the improved tool 40 isone tenth or less than the leading edge radius R₁, the surface appearsto have been polished. The finishing process also seals any pores thatcould allow air to escape from a pneumatic tire mounted upon the wheel.Accordingly, the inventors expect that the number of “leakers” will bereduced.

The invention further contemplates applying a layer of chrome plating 50to the wheel disc face following the work hardening process. The layerof chrome plating 50 covers the smoothed portion of the wheel andprovides an esthetically pleasing appearance. The inventors have foundthat the smoothing of the wheel surface described above eliminates theharmonically distorted pressures experienced with conventional polishingand buffing processes. Additionally, there is minimal wave effect in thewheel surface and the geometric edges of the wheel face are not roundedor softened by the abrasive effects of conventional polishing andbuffing operations. The inventors have found that use of the presentinvention results an a clarity of the surface of the aluminum chromeplated wheel that is at a level comparable to a surgical reflectivemirror or a cosmetic mirror such as used in a compact or powder room.

The invention further contemplates a process for smoothing the wheelface that is illustrated by the flow chart shown in FIG. 7. Steps shownin FIG. 7 which are similar to steps shown in the flow charts in FIGS. 1and 2 and have the same numerical designators. In FIG. 7, a vehiclewheel is cast by a conventional casting process, such as, for example,gravity or low pressure casting, in functional block 10. In functionalblocks 11 through 15, the wheel casting is machined to a final shape asdescribed above; however, a small amount of material is left for a finalfinishing cut with the special tool 40 described above.

In functional block 51, the outboard wheel face is smoothed on a wheellathe or other conventional wheel finishing machine with a finalfinishing cut. The wheel is rotated upon the wheel lathe while a cuttingtool having the unique geometry described above is urged against theoutboard wheel face with a uniform cutting pressure while also beingmoved radially across the outboard wheel face. In the preferredembodiment, the depth of material removed by the tool 40 is within therange of 0.05 mm to 0.1 mm. Once the desired surface dimensions andfinish have been achieved, the wheel is removed from the wheel lathe infunctional block 52.

The wheel surface is then finished with one or more chrome plated layersdeposited by a conventional chrome plating process in functional block25. The present invention contemplates that smoothing is included as oneof the steps in the prior art process for machining a wheel casting. Forexample, a cutting tool mounted upon a tool holder formed from ananti-vibration material can be added to the turret of the wheel latheused to machine the wheel casting and the smoothing operation includedas one of the programmed machining steps for finishing the wheelcasting. Alternately, a smoothing station, which is dedicated tosmoothing the wheel faces, can be established at the wheel manufacturingfacility.

While the preferred embodiment has been described and illustrated aboveas smoothing the entire outboard wheel face, it will be appreciated thatonly a portion of the wheel face can be smoothed. For example, theesthetic design of the wheel may require that only a portion of thewheel face is to be chrome plated with the remainder remaining asmachined or painted. Accordingly, an alternate embodiment of themanufacturing process described above is illustrated by the flow chartshown in FIG. 8. As before, blocks shown in FIG. 8 that are similar toblocks shown in preceding figures have the same numerical designators.In FIG. 8, only the portion which is desired to be chrome plated issmoothed in functional block 51 by a final finishing cut with thespecial tool 40. Therefore, the portions of the wheel surface that arenot to be chrome plated are machined to their final dimensions infunctional block 14. As before, the wheel is removed from the wheellathe in functional block 52. An electrically non-conductive coating isapplied to the non-smoothed portions of the wheel in functional block54. In the preferred embodiment, the portions of the wheel surface thatwere smoothed in functional block 51 are masked before the coating isapplied. For example, the portions of the wheel surface adjacent to thewindows formed between the wheel spokes may be coated while theremainder of the wheel face is chrome plated. Also in the preferredembodiment, the coating is a paint that includes pigment to add color tothe coated area. Alternately, the wheel surface can be covered with aclear coating or the coating may include both a layer of paint and alayer of clear coat that covers the paint. It is further contemplatedthat the coating may include an inert ingredient to further enhance theappearance of the wheel. In the preferred embodiment, the coating issprayed onto the wheel surface and then cured. Once the coating hascured, the masking material is removed. Alternately, a spraying mask maybe used to in place of masking material to control the application ofthe coating to the wheel surface. Finally, in functional block 25, thewheel is chrome plated by a conventional process, such as byelectrolysis with immersion in a tank. Upon immersion, the electricallynon-conductive coating prevents adhesion of the chrome platingchemicals. Instead, the chrome plating chemicals only adhere to the baremetal portions of the wheel surface.

Another alternate manufacturing process is illustrated in FIG. 9, where,as before, blocks that are similar to blocks shown in preceding figureshave the same numerical designators. In FIG. 9, the coating is appliedto the wheel in functional block 54 before the portions of the wheelface are smoothed with the special tool 40 in functional block 54. Inthe preferred embodiment, the entire wheel face is coated in functionalblock 54. Then, when the portions of the wheel surface to be chromeplated are smoothed by the special tool 40 in functional block 51, thetool 40 removes the coating from the portions of the face of the wheelto be chrome plated as it smoothes them. Thus, it is not necessary tomask portions of the wheel. As before, an electrically non-conductivematerial is sprayed onto the wheel face in functional block 54 and thencured. As described above, the coating material can be a paint thatincludes pigment, a clear coat or multiple layers of paint and clearcoat. Additionally, an inert ingredient may be added to the coatingmaterial to further enhance the appearance of the wheel. Alternately, asdescribed above, masking material or a spray mask can be used torestrict the coating material to only the portions of the wheel surfacethat are not to be chrome plated. Once the coating is cured, theportions of the wheel face that are to be chrome plated are smoothed infunctional block 51 by a final finishing cut with the special tool 40.Then, in functional block 25, the wheel is chrome plated by aconventional process, such as by electrolysis with immersion in a tank.Upon immersion, the electrically non-conductive coating preventsadhesion of the chrome plating chemicals. Instead, the chrome platingchemicals only adhere to the bare metal portions of the wheel surface.

The invention also contemplates that the entire surface of wheel can besmoothed to provide an improvement in the cosmetic appearance to thewheel. Also, while the preferred embodiment has been described as beingapplied to cast wheels, it will be appreciated that the cosmeticappearance of wheels formed by other conventional processes also can beimproved by application of the present invention. For example, thepresent invention also contemplates smoothing the outboard surface offorged or stamped wheel discs. Additionally, while the preferredembodiment has been illustrated and described for aluminum or aluminumalloy wheels, it will be appreciated that the invention also may bepracticed on wheels formed from other metals and alloys of other metals.Finally, a layer of clear coat may be optionally applied to the chromeplated surface (not shown).

The inventors expect that using the improved cutting tool to cut andsmooth the wheel face to enhance the cosmetic appearance thereof willcost less than buffing or polishing of the wheel face. Also, because thewheel can be smoothed on existing wheel lathes, no capital cost forpolishing machines is required. The smoothing process eliminates boththe exposure of personnel to toxic substances utilized during polishingand the expense of disposing of the toxic wastes generated thereby.Production time and cost will also be reduced since the need to ship thewheel to a polishing contractor will be eliminated. The improved cuttingtool can extend into the wheel rim to reach the surface of a recessedwheel disc, which can be difficult to reach with polishing wheels. Thecutting and smoothing preserves crisp edge surfaces which may beaesthetically desirable. Such edges tend to be blunted or removed by theabrasive nature of the polishing process. While polishing tends tohighlight surface imperfections, cutting and smoothing tends to hidesuch surface imperfections. Finally, as described above, the presentinvention results in a significantly improved surface appearance and agreatly enhanced appearance of any chrome plating applied over thesmoothed surface.

The invention also contemplates an alternate embodiment of the specialsmoothing tool 60 that is illustrated generally at 60 in FIGS. 10 and11. Components shown in FIGS. 10 and 11 that are the same as componentsshown in previous figures have the same numerical identifiers. The tool60 has a rhombic shaped body 42 having a bore 43 formed therethroughwhich receives a fastener (not shown) for securing the tool to the toolholder 41. The tool 40 is formed from a sintered carbide steel andincludes an insert 64 attached to one end. The insert 64 is formed froma mono crystalline material which may be either naturally occurring orsynthetically produced. In the preferred embodiment, the insert 64 isformed from a Single Crystalline Diamond (SCD) material. The insert 64includes an improved cutting tip 65 on one end that contacts the wheelface 31 and works the metal. The arrow in the upper left portion of FIG.10 indicates the direction of movement of the worked metal, or thewheel, relative to the smoothing tool 40. As before, the insert 64 has alength L of about six mm.

Use of a mono crystalline insert 64 in place of the poly crystallineinsert 44 described above significantly reduces the cost or the insert.Additionally, the use of a mono crystalline material allows a cuttingtip 65 that is symmetrical about the centerline of the tool. In thepreferred embodiment, the radius of the cutting tip, R, is formed in aratio to the length of the tool 60 of about 1 to 16.

As best seen in FIG. 11, the insert 64 is canted at an angle α relativeto the top surface 66 of the tool body 42. In the preferred embodiment,the angle α is seven degrees. A flat land 68 is formed around the upperedge of the insert 64. The land 68 is perpendicular, or has zero rake,to the tool body top surface 66. Because the insert 64 is cantedrelative to the tool body 42, the cutting edge of the insert 64 alsoforms an angle of α with the tool body top surface. Thus, the cuttingtip 65 of the insert 64 is maintained tangent to the surface of the faceof the vehicle wheel. The land 68 has a width W that is in the range ofbetween 0.076 and 0.254 mm with the preferred embodiment having a widthin the range of 0.076 to 0.127 mm. The lower portion 69 of the insert 64and the tool body 42 are undercut at an angle β to allow removal of thecut material. The angle β is in the range of five to 15 degrees and isfive degrees in the preferred embodiment.

Similar to the poly crystalline insert 44 described above, the presentinvention contemplates that, in the preferred embodiment, the feed rateper revolution for a wheel lathe utilizing the tool 60 having themono-crystalline insert 64 is less that the cutting tip radius R.

The invention also contemplates applying a poly or mono crystallinecoating to a substrate to form the tool insert (not shown). Theinventors believe that either a diamond or ceramic coating may beutilized. The coating would be applied either before or after thegeometry of the cutting tip is formed.

The invention further contemplates applying a layer of clear coatingover the entire outboard surface of the wheel to include the chromeplated portion (not shown); however, this step is optional.

In accordance with the provisions of the patent statutes, the principleand mode of operation of this invention have been explained andillustrated in its preferred embodiment. However, it must be understoodthat this invention may be practiced otherwise than as specificallyexplained and illustrated without departing from its spirit or scope.For example, while the preferred embodiment has been described for a onepiece vehicle wheel, it will be appreciated that the invention also canbe practiced upon two piece vehicle wheels having cast full face modularwheel discs. Also, the invention can be practiced upon a wheel spiderwhich is disposed within a wheel rim.

1-23. (canceled)
 24. A cutting tool for smoothing a wheel surfacecomprising: a body; and a cutting tip formed upon one end of the bodyportion, said cutting tip having arcuate leading and trailing edges,said cutting tip also having a zero degree land formed thereaboutwhereby a cutting edge of the tool is maintained tangent to a surface ofthe wheel.
 25. The cutting tool according to claim 24 wherein said bodyhas a rhombic shape and further wherein said body also has a mountingaperture formed therethrough.
 26. The cutting tool according to claim 24wherein said cutting tip is formed upon a non-symmetrical insert carriedupon one end of said body portion, said insert having arcuate leadingand trailing edges, said leading edge having a leading edge radius andsaid trailing edge having a trailing edge radius, said leading edgeradius being greater than the trailing edge radius
 27. The cutting toolaccording to claim 26 wherein said insert is formed from a hardsubstance.
 28. The cutting tool according to claim 27 wherein saidinsert is formed from a poly-crystalline material.
 29. The cutting toolaccording to claim 27 wherein said insert is formed from amono-crystalline material.
 30. The cutting tool according to claim 26wherein said insert is coated with a hard material.
 31. The cutting toolaccording to claim 30 wherein said coating material is one of a diamondand ceramic substance.
 32. The cutting tool according to claim 26wherein said leading edge radius is twice said trailing edge radius. 33.The cutting tool according to claim 26 wherein said end of said bodyadjacent to said tip is undercut by an angle in the range of five to 15degrees.
 34. The cutting tool according to claim 33 wherein said insertis canted relative to a surface of said tool body.
 35. The cutting toolaccording to claim 34 further including a tool holder formed from aanti-vibration material.
 36. The cutting tool according to claim 24wherein the cutting tool includes a non-symmetrical working tip havingarcuate leading and trailing edges, said leading edge having a leadingedge radius and said trailing edge having a trailing edge radius, saidleading edge radius being greater than said trailing edge radius. 37.The cutting tool according to claim 36 wherein said working tip isformed from a hard substance.
 38. The cutting tool according to claim 37wherein said working tip is formed from a poly-crystalline material. 39.The cutting tool according to claim 37 wherein said working tip isformed from a mono-crystalline material.
 40. The cutting tool accordingto claim 36 wherein said working tip is coated with a hard material. 41.The cutting tool according to claim 40 wherein said coating material isone of a diamond and ceramic substance.
 42. The cutting tool accordingto claim 36 wherein said leading edge radius is twice said trailing edgeradius.
 43. The cutting tool according to claim 36 wherein said end ofsaid body adjacent to said tip is undercut by an angle in the range offive to 15 degrees.
 44. The cutting tool according to claim 43 whereinsaid working tip is canted relative to a surface of said tool body. 45.The cutting tool according to claim 44 further including a tool holderformed from a anti-vibration material.
 46. A process for forming adecorative surface upon a wheel surface, the method comprising the stepsof: (a) providing a cutting tool for smoothing at least a portion of thewheel surface that includes a body having a mounting aperture formedtherethrough and a cutting tip formed upon one end of the body portion,the cutting tip having arcuate leading and trailing edges, the cuttingtip also having a zero degree land formed thereabout whereby the cuttingedge of the tool is maintained tangent to the wheel surface. (b)mounting a machined vehicle wheel upon a lathe; (c) rotating the wheel;and (d) urging the cutting tool provided in step (a) with a uniformpressure against a surface of the wheel and traversing the cutting toolacross the surface of the wheel to smooth at least a portion of thewheel surface such that the smoothed portion of the wheel surface has apolished appearance.
 47. The process according to claim 46 wherein thetool provided in step (a) includes a non-symmetrical working tip havingarcuate leading and trailing edges, the leading edge having a leadingedge radius and the trailing edge having a trailing edge radius, theleading edge radius being greater than the trailing edge radius
 48. Theprocess according to claim 47 wherein step (d) includes a rate of feedper revolution of the lathe that is less than the leading edge radius ofthe cutting tool.
 49. The process according to claim 48 wherein step (d)includes a rate of feed per revolution of the lathe that is one tenth ofthe leading edge radius of the cutting tool.